There has been a dramatic increase in the non-medical use of prescription drugs (NMUPD; i.e., without a doctor's prescription) among young adults and adolescents. In 2011, NMUPD was the second most prevalent category of illicit drug use in these age groups, following marijuana. Indeed, NMUPD is involved in more emergency room (ER) visits than use of all illicit substances combined. The recent rise in the non-medical use of prescription stimulants (NMUPS), medications used to treat Attention Deficit Hyperactivity Disorder (ADHD), such as Adderall and Ritalin, is particularly concerning. ER visits related to misuse of these drugs has more than tripled between 2005 and 2010. One relevant concern regarding stimulant misuse, especially with adolescents, is their role in appetite suppression. Given the increasing number of adolescents who report engaging in weight loss behaviors, misuse of stimulants for weight control might appeal to some youth. However, there has been minimal empirical research on this topic, and the majority has exclusively included young adults. NMUPS for weight loss is associated with other substance use, disordered eating behaviors, and psychopathology. Because adolescents are the second largest age group to engage in NMUPS, and they are at high risk for disordered eating behaviors, research is warranted to examine this phenomenon in this age group. Thus, the proposed research will examine this behavior in a sample of adolescents using both survey and qualitative methods. Constructs assessed will include: NMUPS and motivations, consequences associated with NMUPS, medication knowledge, other recreational drug use, disordered eating, psychopathology, and Theory of Planned Behavior (TPB) constructs: attitudes, subjective norms, and perceived control related to NMUPS for weight loss. Key hypotheses are as follows: 1) at least some participants will report NMUPS for weight loss; 2) individuals who engage in NMUPS for weight loss will also engage in more problematic health behaviors and have poorer psychosocial health compared to those who are trying to lose weight without engaging in NMUPS, and those who are not trying to lose weight; 3) these individuals will demonstrate maladaptive cognitions, including higher perceived normality of the behavior and less knowledge about the dangers of such misuse. A multivariate analysis of covariance, correlations, regressions, chi-squares, and thematic analysis of qualitative data will be used to test these hypotheses. Results will provide insight into which modifiable factors are most strongly associated with NMUPS for weight loss, informing awareness, prevention, and intervention efforts. This project will also provide a solid foundation for my research career and facilitate my transition to research independence.